A google search doesn't help much because there are so many theories on it's origin. The theory that made to most sense to me was that it was a satirical song about a revolution that would bring down the House of Stuart by the Protestants. How it became a common lullabye I couldn't tell you but folks are strange and have been known to do strange things. Would be a fun mother to be or mommy fashion fabric for those who love irony and a good laugh shared with friends and strangers.